This invention relates to animal feeds. More particularly, this invention relates to animal feeds that contain an agricultural byproduct and a fibrous portion from milling.
Liquid byproducts from agricultural processing may have a number of uses, including uses as animal feeds. Such liquid byproducts may include any byproduct in agricultural processing that is not the primary product derived from a crop, such as corn. Steepwater, which is an agricultural byproduct from the corn wet milling process, is sometimes used as a feed for dairy cows and other livestock. Many other byproducts result from processing agricultural materials, e.g., cheese production, oil seed extraction, alcohol production, sucrose refining, amino acid, organic acid and mono-sodium glutamate production, and paper and wood production. Byproducts from these and other process may be used as animal feed. Many liquid byproducts from agricultural processing, such as steepwater, contain energy and many of the nutrients (for example, crude protein, fiber, minerals, and fat) needed by animals for economical growth and development.
Many agricultural byproducts, such as steepwater, have a lower monetary value than the primary product from the agricultural processing. In addition, the use of many agricultural byproducts as feed may have one or more of the following disadvantages, which are illustrative for steepwater. Steepwater is usually expensive to transport and store due to its physical characteristics. Generally, steepwater is a heavy, wet product with a somewhat viscous character. Some attempts to remove moisture from the steepwater have often not been effective because the expense of the energy necessary to do so and the fact that steepwater usually is hygroscopic, with an affinity for absorbing atmospheric moisture. Thus steepwater is often a thick, highly viscous product that may be difficult to handle. Because of the expense in removing moisture and the tendency of steepwater to absorb ambient moisture from the atmosphere, steepwater is typically handled in a liquid state, which requires liquid storage tanks, tanker trucks or tanker railcars for transportation, and pumps and pipes to move the product.
Secondary fermentation is an additional problem in using steepwater as a feedstuff. For example, when steepwater is stored for an extended period during transportation or prior to use, e.g., 5-30 days, one often encounters foaming and product degradation brought about by the secondary fermentation. Because of secondary fermentation, the product may therefore have a short shelf life. Secondary fermentation may occur in a tanker railcar during transport or in a feeder""s storage tank. The fermentation of product in the tank causes the steepwater to foam and typically run out of the top of the tank, which not only makes a mess, but also wastes the product. To control secondary fermentation, users often adjust the pH of the steepwater with acids. Anti-microbial agents, such as sodium metabisulfite, may also be added to reduce steepwater secondary fermentation. Other agricultural byproducts may have some or all of the disadvantages of steepwater or may have still other disadvantages.
There is a need for an animal feed that may use the nutritional benefits of an agricultural byproduct and yet have physical characteristics making the use of the feed convenient.
One embodiment of the invention is an animal feed. In this embodiment, the animal feed may have a mixture of a liquid byproduct from agricultural processing and a fibrous portion from milling. The liquid byproduct from agricultural processing may, in one embodiment, be steepwater, and the fibrous portion from milling may be soybean hulls.
Another embodiment of the invention is an animal feed containing a mixture of steepwater and soybean hulls, wherein the steepwater comprises about 5 to about 40 percent by weight of the mixture on a dry basis. In yet another embodiment, the animal feed contains about 5 to about 40 percent by weight on a dry basis of steepwater and about 60 to 95 percent by weight on a dry basis of soybean hulls.
Another embodiment of the invention is a method for producing an animal feed. In this embodiment, the method comprises combining a liquid byproduct from agricultural processing with a fibrous portion from milling to form a mixture, and processing the mixture of the agricultural byproduct and the hulls to form a palatable animal feed.